Sounds interesting. not sure how that would work... Embed the fibre optics in the mat somehow?

Maybe some sort of LED light array first, then get a mat with holes in it to go under it.... Then you could use some sort of controller to twinkle the LED's....

Hmmm....

I'd be interested to see what you find. I've never seen anything other than tiles....

But if your going to scrim it anyway... Why not tiles?